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author | W. Felix Handte <w@felixhandte.com> | 2018-04-06 22:52:55 (GMT) |
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committer | W. Felix Handte <w@felixhandte.com> | 2018-04-06 23:28:08 (GMT) |
commit | 5622c276e114c75f11f6171f9fe2295a8b626e89 (patch) | |
tree | a69602c0b3c220476f1085490f25c2f57678d23f /lib/lz4.c | |
parent | d759d0630003b0722e9389c2297c1856ba8e939f (diff) | |
download | lz4-5622c276e114c75f11f6171f9fe2295a8b626e89.zip lz4-5622c276e114c75f11f6171f9fe2295a8b626e89.tar.gz lz4-5622c276e114c75f11f6171f9fe2295a8b626e89.tar.bz2 |
Return to Allowing Early Returns in LZ4_compress_generic()
Or: `goto` Considered Harmful
Or: https://xkcd.com/292/
Diffstat (limited to 'lib/lz4.c')
-rw-r--r-- | lib/lz4.c | 38 |
1 files changed, 17 insertions, 21 deletions
@@ -626,8 +626,6 @@ LZ4_FORCE_INLINE int LZ4_compress_generic( BYTE* op = (BYTE*) dest; BYTE* const olimit = op + maxOutputSize; - ptrdiff_t retval = 0; - U32 forwardH; /* Init conditions */ @@ -637,6 +635,19 @@ LZ4_FORCE_INLINE int LZ4_compress_generic( dictLowLimit = dictionary ? dictionary : lowLimit; if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */ + + /* Update context state */ + if (dictDirective == usingDictCtx) { + /* Subsequent linked blocks can't use the dictionary. */ + /* Instead, they use the block we just compressed. */ + cctx->dictCtx = NULL; + cctx->dictSize = (U32)inputSize; + } else { + cctx->dictSize += (U32)inputSize; + } + cctx->currentOffset += (U32)inputSize; + cctx->tableType = tableType; + if (inputSize<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */ /* First Byte */ @@ -697,7 +708,7 @@ LZ4_FORCE_INLINE int LZ4_compress_generic( token = op++; if ((outputLimited) && /* Check output buffer overflow */ (unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit))) - goto _clean_up; + return 0; if (litLength >= RUN_MASK) { int len = (int)litLength-RUN_MASK; *token = (RUN_MASK<<ML_BITS); @@ -737,7 +748,7 @@ _next_match: if ( outputLimited && /* Check output buffer overflow */ (unlikely(op + (1 + LASTLITERALS) + (matchCode>>8) > olimit)) ) - goto _clean_up; + return 0; if (matchCode >= ML_MASK) { *token += ML_MASK; matchCode -= ML_MASK; @@ -796,7 +807,7 @@ _last_literals: { size_t const lastRun = (size_t)(iend - anchor); if ( (outputLimited) && /* Check output buffer overflow */ ((op - (BYTE*)dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize) ) - goto _clean_up; + return 0; if (lastRun >= RUN_MASK) { size_t accumulator = lastRun - RUN_MASK; *op++ = RUN_MASK << ML_BITS; @@ -809,22 +820,7 @@ _last_literals: op += lastRun; } - retval = (((char*)op)-dest); - -_clean_up: - if (dictDirective == usingDictCtx) { - /* Subsequent linked blocks can't use the dictionary. */ - /* Instead, they use the block we just compressed. */ - cctx->dictCtx = NULL; - cctx->dictSize = (U32)inputSize; - } else { - cctx->dictSize += (U32)inputSize; - } - cctx->currentOffset += (U32)inputSize; - cctx->tableType = tableType; - - /* End */ - return (int)retval; + return (int)(((char*)op) - dest); } |